Drospirenone has the chemical name of 6β,7β,15β,16β-dimethylene-3-oxo-17α-pregn-4-ene-21,17-carbolactone, CAs#:67392-87-4, molecular formula: C24H30O3, molecular weight: 366.49, and its structural formula is as follows:

Drospirenone is the fourth-generation progestogen developed by German Schering, initially available in German in November, 2000 and now on the markets of United States of America and most European countries. This product has activities of both anti-mineralocorticoid and antiandrogen: the antiandrogen decreases the sebaceous gland activity and the adverse reaction; and the anti-mineralocorticoid lowers excretion of sodium and water, fluid retention and weight gain as well as symptoms associated with menstruation. Meanwhile, the drospirenone has little impact on blood pressure or blood lipid, and has the function of losing weight and maintaining health. Many women choose this product for better skin, hair, mood, and more stable weight. As it has these unique characteristics, now drospirenone has become the preferred contraceptive in foreign countries.
European patent EP0075189 discloses a synthetic method of drospirenone as follows:
The synthetic method disclosed in the patent has potential safety risk as the explosive combustible catalyst and hydrogen are used. In addition, because the dehydration is conducted under the alkaline condition, this may cause the sipro ring to open and be re-arranged.
Chinese patent CN101092443 discloses a new synthetic method of drospirenone as follows:
In this method, the dehydration is also conducted under the alkaline, this may cause the sipro ring to open and be re-arranged. Moreover, the method is more complicated.